CN108462150A - leakage protection circuit and method - Google Patents
leakage protection circuit and method Download PDFInfo
- Publication number
- CN108462150A CN108462150A CN201810143966.9A CN201810143966A CN108462150A CN 108462150 A CN108462150 A CN 108462150A CN 201810143966 A CN201810143966 A CN 201810143966A CN 108462150 A CN108462150 A CN 108462150A
- Authority
- CN
- China
- Prior art keywords
- switch
- circuit
- input terminal
- voltage
- poor contact
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 8
- 238000001514 detection method Methods 0.000 claims abstract description 140
- 230000008859 change Effects 0.000 claims abstract description 33
- 238000012512 characterization method Methods 0.000 claims description 11
- 230000005611 electricity Effects 0.000 claims description 11
- 238000007689 inspection Methods 0.000 claims description 8
- 210000001367 artery Anatomy 0.000 claims description 2
- 238000004080 punching Methods 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 claims description 2
- 210000003462 vein Anatomy 0.000 claims description 2
- 238000005259 measurement Methods 0.000 claims 2
- 238000012544 monitoring process Methods 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 6
- 238000005070 sampling Methods 0.000 description 5
- 239000000243 solution Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011900 installation process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000003637 basic solution Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/44—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to the rate of change of electrical quantities
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/62—Testing of transformers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/06—Details with automatic reconnection
- H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
- H02H9/025—Current limitation using field effect transistors
Abstract
The invention discloses a kind of leakage protection circuit and methods comprising current detection circuit judges input terminal with the presence or absence of electric leakage according to first switch electric current is flowed through；Poor contact detection circuit, according to the voltage change ratio of the pressure difference or first switch first end of the electric current or input terminal voltage change rate or the first terminal voltage of first switch or first switch first end and second end that flow through first switch or the pressure difference change rate of first switch first end and second end, it is bad to judge whether input terminal is in contact；Control circuit controls first switch turn-on and turn-off, and during first switch is connected, current detection circuit detects the electric current for flowing through first switch, and current detection signal is less than first threshold, turns off first switch；Current detection signal reaches first threshold, and first switch continues to be connected, and it is bad that poor contact detection circuit judges whether input terminal is in contact, if being in contact bad, shutdown first switch.The present invention protects switching tube when input terminal poor contact or voltage become larger suddenly.
Description
Technical field
The present invention relates to power electronics fields, more specifically, being related to a kind of earth leakage protective circuit and method.
Background technology
In loading installation process, because of the logical situation of possible generating unit tap during the installation process, if human body is not small at this time
The heart contacts, then is easy to get an electric shock, influences safety operation.For example, in lighting area, since more lamp holder also maintains both-end access
Interface, when being replaced to original fluorescent tube, fluorescent tube general or using double-width grinding.The double-width grinding refer to by
The connector of ac input end is respectively provided at lamp tube ends, and in this case, lamp is generally first inserted into one end therein by operator
Seat, is then inserted into the other end, since operator's hand needs to grasp, in the end of fluorescent tube, to be likely to be exposed the gold of end conduction
The case where belonging to, being easy to happen electric shock, therefore be important to the earth leakage protective in the case of this kind.
It is connected with switching tube in power supply and power stage circuit in the prior art, is first connected when starting entire circuit work
Switching tube detects the electric current by switching tube, using the size of the electric current to determine whether leaky occurs, when the electric current is small
When given threshold, when determining input terminal generation leaky, on-off switching tube cuts off entire circuit, to leak electricity
Protection maintains switching tube conducting state if the electric current is more than the threshold value.But it is in the prior art, if normal in entire circuit
After work, power input be in contact it is bad, then can be very big by the electric current of switching tube so that switching tube is easy damage
It is bad.
Invention content
In view of this, the present invention proposes a kind of damage for making it receive in power input poor contact protection switching tube
Evil smaller leakage protection circuit and method, in the prior art in input terminal poor contact, flow through switch for solving
Tube current is larger in turn result in the technical issues of switching tube is easily damaged.
The present invention provides a kind of leakage protection circuits, including：
Current detection circuit, detection flow through the electric current for being connected to the first switch on major loop, obtain characterization and flow through first
The current detection signal of switching current, the current detection signal are less than first threshold, then it is existing to judge that input terminal has electric leakage
As；
Poor contact detection circuit is opened according to the electric current or input terminal voltage change rate or described first that flow through first switch
It closes the voltage of first end or the pressure difference of the first switch first end and second end or the voltage of the first switch first end becomes
The pressure difference change rate of rate or the first switch first end and second end, judges whether input terminal is in contact bad phenomenon；
Control circuit controls the turn-on and turn-off of first switch, during the first switch conducting, the current detecting electricity
Road, which is detected, flows through the electric current of first switch, if the current detection signal is less than first threshold, control circuit control described the
One switch OFF；If the current detection signal reaches first threshold, the first switch continues to be connected, the poor contact
Detection circuit judges whether input terminal is in contact bad phenomenon, when the poor contact detection circuit judges that input terminal connects
When touching bad phenomenon, control circuit controls the first switch shutdown.
Optionally, the leakage protection circuit further includes voltage detecting circuit, voltage detecting circuit detection input voltage
Or the voltage of the first switch first end or the pressure difference of the first switch first end and second end, obtain voltage detecting letter
Number, the voltage detection signal reaches second threshold, and control circuit controls the first switch conducting, current detection circuit detection
Flow through the electric current of first switch.
Optionally, after the first switch shutdown, current detection circuit carries out detection of electrical leakage again.
Optionally, poor contact detection circuit detection flows through the electric current of the first switch, when flowing through described first
When the electric current of switch reaches third threshold value, it is bad that the poor contact detection circuit judges that input terminal is in contact.
Optionally, the poor contact detection circuit includes first comparator, the first input end of the first comparator
Receive the current detection signal that characterization flows through the electric current of first switch, the second input terminal of the first comparator receives described the
Three threshold values, when the current detection signal reaches third threshold value, then the first comparator overturning, the first comparator it is defeated
Outlet connects the control circuit.
Optionally, the poor contact detection circuit detection input voltage, when the change rate of input terminal voltage is more than the
When four threshold values, it is bad that the poor contact detection circuit judges that input terminal is in contact.
Optionally, the poor contact detection circuit includes first resistor, the first capacitance and the second comparator, and described first
One end of capacitance receives the voltage detection signal of characterization input voltage, and the other end of first capacitance connects the one of first resistor
End, the other end ground connection of the first resistor, the first input end of second comparator connect the first resistor and first
Second input terminal of the common end of capacitance, second comparator receives third threshold value, and the output end of second comparator connects
Connect the control circuit.
Optionally, the poor contact detection circuit detects the voltage of the first switch first end or the first switch
The pressure difference of first end and second end, the voltage when the first switch first end or the first switch first end and second end
When pressure difference reaches five threshold values, it is bad that the poor contact detection circuit judges that input terminal is in contact.
Optionally, the poor contact detection circuit detects the voltage of the first switch first end or the first switch
The pressure difference of first end and second end, when the voltage change ratio of the first switch first end or the first switch first end and
When the pressure difference change rate at two ends reaches six threshold values, it is bad that the poor contact detection circuit judges that input terminal is in contact.
Optionally, the first switch is metal-oxide-semiconductor, and the first end of the first switch is drain electrode, the first switch
Second end is source electrode, and the control terminal of the first switch is grid.
Optionally, the control circuit includes pulse generating circuit and logic circuit, the pulse generating circuit it is defeated
Enter end connection logic circuit and poor contact detection circuit, the output end of the pulse generating circuit connect the first switch
Control terminal.
The present invention also provides a kind of earth leakage protecting methods, including：
Detection flows through the electric current for being connected to the first switch on major loop, obtains the electric current that characterization flows through first switch electric current
Signal is detected, the current detection signal is less than first threshold, then judges that there are leakies for input terminal；
According to the voltage for the electric current or input terminal voltage change rate or the first switch first end for flowing through first switch or
The voltage change ratio of the pressure difference of the first switch first end and second end or the first switch first end described first is opened
The pressure difference change rate for closing first end and second end, judges whether input terminal is in contact bad phenomenon；
The turn-on and turn-off of first switch are controlled, during the first switch conducting, the current detection circuit detection stream
Electric current through first switch, if the current detection signal is less than first threshold, control circuit controls the first switch and closes
It is disconnected；If the current detection signal reaches first threshold, the first switch continues to be connected, the poor contact detection circuit
Judge whether input terminal is in contact bad phenomenon, when to judge that input terminal is in contact bad existing for the poor contact detection circuit
As when, control circuit controls first switch shutdown.
Compared with prior art, the technical solution of the present invention has the following advantages：The present invention overcomes the prior arts because defeated
Enter end in contact it is bad and caused by first switch the technical issues of being easily damaged, current detection circuit judges that input terminal leaks electricity
Phenomenon then turns off the first switch, and current detection circuit judges that leaky does not occur for input terminal, then the first switch after
Continuous conducting, the poor contact detection circuit detection flow through the electric current of first switch or the change rate of input terminal voltage, judge defeated
Enter end and whether be in contact bad, if input terminal is in contact bad, disconnects the first switch, then re-start electric leakage inspection
It surveys.Poor contact detection circuit is added in the present invention on the basis of leakage protection circuit prior art so that in power input
In the case that poor contact and voltage become larger suddenly, protection switching tube keeps the damage that it receives smaller.
Description of the drawings
Fig. 1 is the structural schematic diagram of leakage protection circuit embodiment one of the present invention；
Fig. 2 is the detection principle diagram of poor contact detection circuit in the embodiment of the present invention one；
Fig. 3 is the physical circuit of poor contact detection circuit in the embodiment of the present invention one.
Fig. 4 is the structural schematic diagram of leakage protection circuit embodiment two of the present invention；
Fig. 5 is the detection principle diagram of poor contact detection circuit in the embodiment of the present invention two；
Fig. 6 is the physical circuit of poor contact detection circuit in the embodiment of the present invention two；
Fig. 7 is the structural schematic diagram of leakage protection circuit embodiment three of the present invention.
Specific implementation mode
The preferred embodiment of the present invention is described in detail below in conjunction with attached drawing, but the present invention is not restricted to these
Embodiment.The present invention covers any replacement made in the spirit and scope of the present invention, modification, equivalent method and scheme.
In order to make the public have thorough understanding to the present invention, it is described in detail in following present invention preferred embodiment specific
Details, and description without these details can also understand the present invention completely for a person skilled in the art.
The present invention is more specifically described by way of example with reference to attached drawing in the following passage.It should be noted that attached drawing is adopted
Use with more simplified form and non-accurate ratio, only to it is convenient, lucidly aid in illustrating the embodiment of the present invention
Purpose.
The basic solution of the present invention, the leakage protection circuit include current detection circuit, poor contact detection
Circuit, control circuit, wherein in the present solution,
The current detection circuit detection flows through the electric current for the first switch first switch M1 being connected on major loop, obtains
Characterization flows through the current detection signal of first switch M1 electric currents, judges input terminal with the presence or absence of leakage according to the current detection signal
Electrical phenomena.
The poor contact detection circuit, according to the electric current or input terminal voltage change rate for flowing through first switch or described
The voltage or the pressure difference of the first switch first end and second end or the electricity of the first switch first end of one switch first end
It is bad existing to judge whether input terminal is in contact for the pressure difference change rate of buckling rate or the first switch first end and second end
As；
The turn-on and turn-off of the control circuit control first switch M1, during the first switch M1 conductings, the electricity
Current detection circuit detects the electric current for flowing through first switch M1, if the current detection signal is less than first threshold, by control electricity
Road controls the first switch M1 shutdowns；If the current detection signal reaches first threshold, the first switch M1 continues
Conducting, the poor contact detection circuit judge whether input terminal is in contact bad phenomenon, when the poor contact detects electricity
When road judges that input terminal is in contact bad phenomenon, the first switch M1 is controlled by control circuit and is turned off, restarts to carry out
Detection of electrical leakage.
The major loop, as operating circuit, the first switch M1 can control the turn-on and turn-off of major loop.It is described
The control terminal of first switch M1 is connect with the control circuit, by the turn-on and turn-off of control circuit control first switch M1.
In the present invention, in the current detection circuit detection of electrical leakage stage, directly it can utilize high level that first switch M1 is connected,
If leaky does not occur for judgement, conducting first switch M1 is continued directly to.Can also detection of electrical leakage be controlled by pulse signal,
If leaky does not occur for judgement, then first switch M1 is connected in high level, and the triggering of the high level may be in pulse signal
High level or low level at.Described continues to be connected, it may be possible to constantly on, it is also possible to of short duration to stop after the completion of detection
It is connected after.
The leakage protection circuit can also include voltage detecting circuit, and what voltage detecting circuit can detect is input terminal
Voltage, then at this time two input terminals of voltage detecting circuit be connected to the both ends of rectifier bridge, alternating current input power supplying both ends
Or an output end of rectifier bridge and wherein one end of alternating current input power supplying, unless otherwise indicated, power input either
Ac input end can also be the output end of rectifier bridge.Voltage detecting circuit can also detect the first switch first end
The pressure difference of voltage or the first switch first end and second end, then two input terminals of voltage detecting circuit are respectively institute at this time
State the first end and second end of first switch first end and ground or the first switch.Voltage detecting circuit in the case of two kinds
Output end is connect with control circuit, when voltage detecting circuit detects input terminal voltage or the voltage of the first switch first end
Or the pressure difference of the first switch first end and second end, when being second threshold, the control circuit controls the first switch M1
Conducting, the current detection circuit detection flow through the electric current of first switch M1.The advantage is that it can be by using voltage detecting circuit
Voltage detecting circuit determines a threshold value, i.e., is detected in second threshold, that is to say, that input voltage at this time is certain
, it is during this time connected first switch M1 and carries out current detecting, obtained current detection signal actually characterizes
The internal resistance of circuit, internal resistance whether due to electric leakage are different (i.e. whether someone's body impedance accesses), draw if human body access occurs
Drain conditions are played, can be characterized by the current detection signal.
The mode of control first switch M1 turn-on and turn-off has very much, using pulse generating circuit come real in the present embodiment
It is existing.
As shown in Figure 1, illustrating one structure chart of embodiment using leakage protection circuit of the present invention, the control circuit packet
Logic circuit and pulse generating circuit are included, the voltage detecting circuit connects the arteries and veins with current detection circuit by logic circuit
Circuit occurs for punching, and the poor contact detection circuit sampling passes through the electric current of first switch M1, output end connection pulse generation electricity
Road, the control terminal of the pulse generating circuit connection first switch M1.
It includes bleeder circuit and comparator comp4 that the voltage detecting circuit, which includes the voltage detecting circuit, described
Bleeder circuit is composed in series by resistance R2 and R3, two input terminal is connected to the both ends of rectifier bridge, alternating current input power supplying
Both ends or an output end of rectifier bridge and wherein one end of alternating current input power supplying, dotted portion indicates possible connection in figure
Mode is illustrated and is illustrated in figure to connection type.The first input end of the comparator comp4 connects bleeder circuit
Output end be resistance R2 and R3 common end, the second input terminal of the comp4 of comparator, which receives, characterizes the second threshold
Signal Vref2, when the voltage detection signal reaches Vref2, then comparator comp4 is overturn, and pulse generating circuit receives
The output signal of comparator comp4, and pulse is sent out, so that first switch M1 is connected, the current detection circuit starts to detect work
Make.
The case where voltage detecting circuit detection input voltage is simply shown in embodiment one, but voltage detecting circuit is examined
It surveys as the voltage of the first switch first end or the pressure difference of the first switch first end and second end also in the guarantor of the present invention
It protects in range.In the following examples two and embodiment three similarly.
In addition, voltage detecting circuit difference detection input voltage and detecting voltage or the detection the of first switch first end
The pressure difference of one switching tube first end and second end, the second threshold differ, and it is convenient to be used for the purpose of narration here.
The current detection circuit includes sampling resistor R0 and comparator comp3, and sampling resistor R0 goes here and there with first switch M1
Connection, during first switch M1 conductings, sampling flows through the electric current of first switch M1, and the first input of input comparator comp3
End, the second input terminal of comparator comp3 receives the signal Vref1 of characterization first threshold, when current detection signal is less than
Vref1 indicates that there are leakies, and level overturning occurs for comparator comp3 output ends at this time, and controls first through logic circuit
Switch M1 is disconnected, and disconnects major loop.If the current detecting reaches Vref1, then it represents that leaky is not present, described first opens
Closing M1 can be with normally.
After major loop works normally, the poor contact detection circuit is started to work, and the poor contact circuit receives
The electric current of first switch M1 is flowed through, the poor contact circuit output end connects the pulse generating circuit.
Driver in Fig. 1 is used for the driving of switching tube, and the control signal of control circuit, which is become suitable for control, to be opened
Logical and shutdown control signal, has no substantial effect circuit theory, therefore omits it in the de-scription, but practical driving is opened
During closing pipe, driver realization is generally required.Those skilled in the art's description according to the present invention, knows and can be accordingly
It is practiced.
The testing principle of poor contact detection circuit described in embodiment one is as shown in Figure 2.Wherein, wherein VAC1It is normal
When input voltage waveform figure, i1 flows through the current waveform figure of first switch M1, V when being normalAC2For input terminal poor contact when it is defeated
Enter voltage oscillogram, i2 is the current waveform figure that first switch M1 is flowed through when input terminal poor contact.Is flowed through when comparing normal
The electric current i2 that the electric current i1 of one switch M1 and when input terminal poor contact flow through first switch M1 can be obtained, and be flowed through by detection
Whether the electric current i of first switch M1 can be in contact bad phenomenon with detection input, when the electric current i for flowing through first switch M1 can
When being more than third threshold value, it may be considered that being in contact bad phenomenon, control circuit remains open the first switch M1.
Its physical circuit figure is as shown in Figure 3.The poor contact detection circuit includes first comparator, the sampling resistor
R0 detections flow through the electric current of first switch M1 and are input to the first input end of comparator comp1, the comparator comp1's
Second input terminal receives third threshold value, and the output of the comp1 connects the pulse generating circuit, first switch is flowed through when described
The electric current of M1 reaches third threshold value, and the comparator comp1 overturnings, the impulse generator sends out pulse, so that described
First switch turns off.
As shown in figure 4, illustrating one structure chart of embodiment using leakage protection circuit of the present invention.The wherein described contact is not
Good detection circuit receives the signal for characterizing the input terminal voltage, and output end is connected to pulse generating circuit, rest part and Fig. 1
It is identical.
Fig. 5 gives the detection principle diagram of poor contact detection circuit in the embodiment of the present invention two.Wherein VAC1It is normal
Input voltage waveform figure, VSLP1For normal voltage change ratio oscillogram, VAC2For the input voltage of input terminal poor contact, VSLP2
For the voltage change ratio oscillogram of input terminal poor contact.Compare normal voltage change rate VSLP1With when input terminal poor contact
Voltage change ratio VSLP2It can obtain, pass through the change rate V of detection input voltageSLPWhether can be connect with detection input
Bad phenomenon is touched, as the change rate V of input terminal voltageSLPWhen can be more than four threshold values, it may be considered that being in contact bad existing
As control circuit is held off first switch M1.
Fig. 6 gives the physical circuit figure that poor contact detection circuit is provided according to Fig. 4 principles.The poor contact detection
Circuit includes resistance R1, one end reception characterization input electricity of the first capacitance C1 and third comparator comp2, the first capacitance C1
The voltage detection signal of pressure, one end of the other end connection resistance R1 of the first capacitance C1, another termination of the resistance R1
Ground, the first input end of the second comparator comp2 connect the common end of the first resistor and the first capacitance, and described second
Second input terminal of comparator receives third threshold value Vref4, and the output end of second comparator connects the control circuit.When
When the first input end value of second comparator is more than third threshold value Vref4, then the level of comparator comp4 output ends generation at this time turns over
Turn, and is disconnected through control circuit control first switch M1.
Fig. 7 illustrates the structure chart of the embodiment three using leakage protection circuit of the present invention, the poor contact circuit
Input terminal receives the voltage of the first switch M1 first ends or the pressure difference of the first switch M1 first end and second ends, described
The pulse generating circuit of the output end of poor contact detection circuit circuit in order to control, when the voltage of the first switch M1 first ends
Or the pressure difference of the first switch M1 first end and second ends, when reaching five threshold values, the control circuit shutdown described first is opened
Close M1.
The voltage or the first switch M1 of first switch M1 first ends when the principle of poor contact detection circuit is normal
The pressure difference of first end and second end be less than the 5th threshold value, when the first switch M1 first ends voltage or the first switch
When the pressure difference of M1 first end and second ends reaches five threshold values, it may be considered that being in contact bad phenomenon, control circuit is kept
Disconnect the first switch M1.
It is embodied in illustration and does not provide, and can be a comparator, and one end connection described first of comparator is opened
First end is closed, the second end of comparator receives the 5th threshold value, and the output of comparator connects pulse generating circuit, the first switch
The voltage of first end reaches the 5th threshold value, and comparator overturning, the impulse generator sends out pulse, so that described first opens
Shutdown.
Poor contact circuit another kind testing principle described in Fig. 7 is：According to the voltage of the first switch M1 first ends
The change rate of change rate or the pressure difference of the first switch M1 first end and second ends, when the first switch M1 first ends
When voltage change ratio or the pressure difference change rate of the first switch M1 first end and second ends reach six threshold values, the control electricity
Road turns off the first switch M1.
Should be noted that poor contact of the present invention, not only include traditional poor contact, i.e., one
The section time does not access voltage, further includes the case where voltage becomes larger suddenly, as lightning surge voltage occurs for input terminal.Therefore, originally
The case where poor contact detection circuit of invention can suddenly be increased with detection input poor contact and all input terminal voltages.
In addition to this, although embodiment is separately illustrated and is illustrated above, it is related to the common technology in part, in this field
Those of ordinary skill apparently, can be replaced and integrate between the embodiments, be related to one of embodiment and record is not known
Content, then can refer to another embodiment on the books.
Embodiments described above does not constitute the restriction to the technical solution protection domain.It is any in above-mentioned implementation
Modifications, equivalent substitutions and improvements etc., should be included in the protection model of the technical solution made by within the spirit and principle of mode
Within enclosing.
Claims (12)
1. a kind of leakage protection circuit, which is characterized in that including：
Current detection circuit, detection flow through the electric current for being connected to the first switch on major loop, obtain characterization and flow through first switch
The current detection signal of electric current, the current detection signal are less than first threshold, then judge that there are leakies for input terminal；
Poor contact detection circuit, according to the electric current or input terminal voltage change rate that flow through first switch or the first switch
The voltage change ratio of the pressure difference or the first switch first end of the voltage of one end or the first switch first end and second end
Or the pressure difference change rate of the first switch first end and second end, judge whether input terminal is in contact bad phenomenon；
Control circuit controls the turn-on and turn-off of first switch, during the first switch conducting, the current detection circuit inspection
Electric current of the flow measurement through first switch, if the current detection signal is less than first threshold, control circuit control described first is opened
Shutdown；If the current detection signal reaches first threshold, the first switch continues to be connected, the poor contact detection
Whether circuit judges input terminal is in contact bad phenomenon, when the poor contact detection circuit judges that input terminal is in contact not
When good phenomenon, control circuit controls the first switch shutdown.
2. leakage protection circuit according to claim 1, it is characterised in that：The leakage protection circuit further includes voltage inspection
The voltage or the first switch first of slowdown monitoring circuit, voltage detecting circuit detection input voltage or the first switch first end
The pressure difference at end and second end obtains voltage detection signal, and the voltage detection signal reaches second threshold, and control circuit controls institute
First switch conducting is stated, current detection circuit detects the electric current for flowing through first switch.
3. leakage protection circuit according to claim 1 or 2, it is characterised in that：After the first switch shutdown, electric current inspection
Slowdown monitoring circuit carries out detection of electrical leakage again.
4. leakage protection circuit according to claim 1 or 2 or 3, it is characterised in that：The poor contact detection circuit inspection
Electric current of the flow measurement through the first switch, when the electric current for flowing through the first switch reaches third threshold value, the poor contact
It is bad that detection circuit judges that input terminal is in contact.
5. leakage protection circuit according to claim 4, it is characterised in that：The poor contact detection circuit includes first
The first input end of comparator, the first comparator receives the current detection signal that characterization flows through the electric current of first switch, institute
The second input terminal for stating first comparator receives the third threshold value, when the current detection signal reaches third threshold value, then institute
First comparator overturning is stated, the output end of the first comparator connects the control circuit.
6. leakage protection circuit according to claim 1 or 2 or 3, it is characterised in that：The poor contact detection circuit inspection
Input terminal voltage is surveyed, when the change rate of input terminal voltage reaches four threshold values, the poor contact detection circuit judges input
End is in contact bad.
7. leakage protection circuit according to claim 6, it is characterised in that：The poor contact detection circuit includes first
Resistance, the first capacitance and the second comparator, one end of first capacitance receive the voltage detection signal of characterization input voltage, institute
State one end of the other end connection first resistor of the first capacitance, the other end ground connection of the first resistor, second comparator
First input end connect the common end of the first resistor and the first capacitance, the second input terminal of second comparator receives
The output end of 4th threshold value, second comparator connects the control circuit.
8. leakage protection circuit according to claim 1 or 2 or 3, it is characterised in that：The poor contact detection circuit inspection
The voltage of the first switch first end or the pressure difference of the first switch first end and second end are surveyed, when the first switch
When the voltage of one end or the pressure difference of the first switch first end and second end reach five threshold values, the poor contact detection electricity
It is bad that road judges that input terminal is in contact.
9. leakage protection circuit according to claim 1 or 2 or 3, it is characterised in that：The poor contact detection circuit inspection
The voltage of the first switch first end or the pressure difference of the first switch first end and second end are surveyed, when the first switch
It is described to connect when the voltage change ratio of one end or the pressure difference change rate of the first switch first end and second end reach six threshold values
It is bad that tactile bad detection circuit judges that input terminal is in contact.
10. leakage protection circuit according to claim 1 or 2 or 3, it is characterised in that：The first switch is metal-oxide-semiconductor,
The first end of the first switch is drain electrode, and the second end of the first switch is source electrode, and the control terminal of the first switch is
Grid.
11. leakage protection circuit according to claim 1 or 2 or 3, it is characterised in that：The control circuit includes arteries and veins
Circuit and logic circuit occur for punching, and the input terminal of the pulse generating circuit connects logic circuit and poor contact detection circuit,
The output end of the pulse generating circuit connects the control terminal of the first switch.
12. a kind of earth leakage protecting method, which is characterized in that including：
Detection flows through the electric current for being connected to the first switch on major loop, obtains the current detecting that characterization flows through first switch electric current
Signal, the current detection signal are less than first threshold, then judge that there are leakies for input terminal；
According to the voltage for the electric current or input terminal voltage change rate or the first switch first end for flowing through first switch or described
The voltage change ratio or the first switch of the pressure difference of first switch first end and second end or the first switch first end
The pressure difference change rate of one end and second end, judges whether input terminal is in contact bad phenomenon；
The turn-on and turn-off of first switch are controlled, during first switch conducting, the current detection circuit detection flows through the
The electric current of one switch, if the current detection signal is less than first threshold, control circuit controls the first switch shutdown；If
The current detection signal reaches first threshold, then the first switch continues to be connected, and the poor contact detection circuit judges
Whether input terminal is in contact bad phenomenon, when the poor contact detection circuit judges that input terminal is in contact bad phenomenon
When, control circuit controls the first switch shutdown.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710085646 | 2017-02-17 | ||
| CN2017100856468 | 2017-02-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108462150A true CN108462150A (en) | 2018-08-28 |
Family
ID=62661540
Family Applications (8)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820241918.9U Active CN208174241U (en) | 2017-02-17 | 2018-02-10 | A kind of leakage protection circuit |
| CN201810139245.0A Pending CN108233332A (en) | 2017-02-17 | 2018-02-10 | A kind of leakage protection circuit and method |
| CN201810140125.2A Pending CN108270195A (en) | 2017-02-17 | 2018-02-10 | leakage protection circuit and method |
| CN201820240165.XU Active CN208174237U (en) | 2017-02-17 | 2018-02-10 | leakage protection circuit |
| CN201820247590.1U Active CN208174246U (en) | 2017-02-17 | 2018-02-11 | leakage protection circuit |
| CN201810143661.8A Pending CN108429236A (en) | 2017-02-17 | 2018-02-11 | A kind of leakage protection circuit and method |
| CN201810143966.9A Pending CN108462150A (en) | 2017-02-17 | 2018-02-11 | leakage protection circuit and method |
| CN201820247694.2U Active CN208174243U (en) | 2017-02-17 | 2018-02-11 | A kind of leakage protection circuit |
Family Applications Before (6)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820241918.9U Active CN208174241U (en) | 2017-02-17 | 2018-02-10 | A kind of leakage protection circuit |
| CN201810139245.0A Pending CN108233332A (en) | 2017-02-17 | 2018-02-10 | A kind of leakage protection circuit and method |
| CN201810140125.2A Pending CN108270195A (en) | 2017-02-17 | 2018-02-10 | leakage protection circuit and method |
| CN201820240165.XU Active CN208174237U (en) | 2017-02-17 | 2018-02-10 | leakage protection circuit |
| CN201820247590.1U Active CN208174246U (en) | 2017-02-17 | 2018-02-11 | leakage protection circuit |
| CN201810143661.8A Pending CN108429236A (en) | 2017-02-17 | 2018-02-11 | A kind of leakage protection circuit and method |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820247694.2U Active CN208174243U (en) | 2017-02-17 | 2018-02-11 | A kind of leakage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (8) | CN208174241U (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN208174241U (en) * | 2017-02-17 | 2018-11-30 | 杰华特微电子（杭州）有限公司 | A kind of leakage protection circuit |
| CN111148309B (en) * | 2018-10-16 | 2023-08-25 | 卡任特照明解决方案有限公司 | Lamp driving circuit and method for operating the same |
| US10976762B2 (en) | 2018-10-26 | 2021-04-13 | Rolls-Royce North American Technologies, Inc. | Control of an electrical power system responsive to sensing a ground fault |
| CN110601134A (en) * | 2019-09-10 | 2019-12-20 | 杰华特微电子（杭州）有限公司 | Leakage protection circuit, protection method and lighting circuit applying leakage protection circuit |
| CN111368500A (en) | 2020-03-06 | 2020-07-03 | 杰华特微电子（杭州）有限公司 | Method for establishing metal interconnection layer capacitance prediction model and model system |
| CN111585244B (en) * | 2020-05-26 | 2022-09-16 | 芯海科技（深圳）股份有限公司 | Leakage protection circuit, integrated circuit, electronic device, and method |
| CN111983440B (en) * | 2020-07-16 | 2023-03-24 | 中广核核电运营有限公司 | Socket detection method and socket detection device |
| CN113014128A (en) * | 2021-03-26 | 2021-06-22 | 安徽电气工程职业技术学院 | DCAC control circuit in domestic dc-to-ac converter |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201122833Y (en) * | 2007-11-19 | 2008-09-24 | 海尔集团公司 | Micro-controlled electricity-saving protection device |
| US20160172999A1 (en) * | 2014-12-10 | 2016-06-16 | Monolithic Power Systems, Inc. | Switching controller with over voltage protection and switching converter and method thereof |
| US20160241226A1 (en) * | 2013-10-30 | 2016-08-18 | Autonetworks Technologies, Ltd. | Overcurrent protection circuit |
| CN105929929A (en) * | 2016-05-13 | 2016-09-07 | 上海墨百意信息科技有限公司 | Circuit for eliminating electric leakage of device in shutdown state |
| CN208174246U (en) * | 2017-02-17 | 2018-11-30 | 杰华特微电子（杭州）有限公司 | leakage protection circuit |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI258909B (en) * | 2005-01-10 | 2006-07-21 | Cable Vision Electronics Co Lt | Overcurrent protection device |
| CN103746342B (en) * | 2014-01-10 | 2016-09-21 | 成都芯源系统有限公司 | Boost converter, controller for boost converter and short-circuit protection method |
| CN204216632U (en) * | 2014-11-27 | 2015-03-18 | 北京拓盛电子科技有限公司 | Battery discharge prevention circuit |
| CN104377647B (en) * | 2014-11-27 | 2018-02-27 | 德力西电气有限公司 | leakage protection circuit |
| CN204205560U (en) * | 2014-11-27 | 2015-03-11 | 德力西电气有限公司 | leakage protection circuit |
| CN204615366U (en) * | 2015-05-19 | 2015-09-02 | 成都欧安电气有限公司 | A kind of double-current defencive function power supply |
| CN105375764B (en) * | 2015-11-11 | 2018-05-29 | 矽力杰半导体技术(杭州)有限公司 | Switch controlled circuit |
| CN106230258B (en) * | 2016-08-29 | 2018-12-14 | 杰华特微电子（杭州）有限公司 | The driving method and circuit and power-supply system of power switch tube |
-
2018
- 2018-02-10 CN CN201820241918.9U patent/CN208174241U/en active Active
- 2018-02-10 CN CN201810139245.0A patent/CN108233332A/en active Pending
- 2018-02-10 CN CN201810140125.2A patent/CN108270195A/en active Pending
- 2018-02-10 CN CN201820240165.XU patent/CN208174237U/en active Active
- 2018-02-11 CN CN201820247590.1U patent/CN208174246U/en active Active
- 2018-02-11 CN CN201810143661.8A patent/CN108429236A/en active Pending
- 2018-02-11 CN CN201810143966.9A patent/CN108462150A/en active Pending
- 2018-02-11 CN CN201820247694.2U patent/CN208174243U/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201122833Y (en) * | 2007-11-19 | 2008-09-24 | 海尔集团公司 | Micro-controlled electricity-saving protection device |
| US20160241226A1 (en) * | 2013-10-30 | 2016-08-18 | Autonetworks Technologies, Ltd. | Overcurrent protection circuit |
| US20160172999A1 (en) * | 2014-12-10 | 2016-06-16 | Monolithic Power Systems, Inc. | Switching controller with over voltage protection and switching converter and method thereof |
| CN105929929A (en) * | 2016-05-13 | 2016-09-07 | 上海墨百意信息科技有限公司 | Circuit for eliminating electric leakage of device in shutdown state |
| CN208174246U (en) * | 2017-02-17 | 2018-11-30 | 杰华特微电子（杭州）有限公司 | leakage protection circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN208174237U (en) | 2018-11-30 |
| CN208174246U (en) | 2018-11-30 |
| CN108429236A (en) | 2018-08-21 |
| CN108233332A (en) | 2018-06-29 |
| CN208174243U (en) | 2018-11-30 |
| CN108270195A (en) | 2018-07-10 |
| CN208174241U (en) | 2018-11-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN208174246U (en) | leakage protection circuit | |
| CN109617005A (en) | Leakage protection circuit and illumination driving circuit | |
| CN208001164U (en) | Charging unit and charging system | |
| CN105244850B (en) | Battery protecting circuit and its control method | |
| CN104155505A (en) | Earth wire live detection device, air conditioner and electrical equipment | |
| CN105403790A (en) | Serially-connected arc fault detection circuit and serially-connected arc fault detection method | |
| CN109787305A (en) | Charging unit and charging system | |
| CN108445360A (en) | A kind of partial discharge of switchgear positioning device and method | |
| CN106771517A (en) | A kind of mobile terminal and its display screen over-current detecting method and system | |
| TW202036008A (en) | Direct-current power supply leakage current detection device that comprises at least one leakage current detection module, a capacitor grounding module, and a malfunction analysis module | |
| CN203350348U (en) | Electrification detection device for ground wire, air-conditioner and electrical equipment | |
| JP6420957B2 (en) | Test apparatus and method | |
| CN104459545A (en) | Control circuit and battery short circuit testing device including control circuit | |
| CN204144597U (en) | Self-inspection confession pattern insert row | |
| CN206432694U (en) | Earth leakage protective device | |
| CN112834950B (en) | Electric leakage detection circuit, electric leakage protection circuit and household appliance | |
| CN108693467A (en) | Switching device for checking switch element | |
| CN201242565Y (en) | Multifunctional combined electroscope | |
| CN110601134A (en) | Leakage protection circuit, protection method and lighting circuit applying leakage protection circuit | |
| CN104201875B (en) | Short circuit protection soft start circuit and method | |
| CN208596188U (en) | Measurement electroprobe with safe identification function | |
| US11672073B2 (en) | Lamp having a safety circuit, and a safety circuit for use in such lamps | |
| JP2004317349A (en) | Failure point detection device | |
| CN104570900B (en) | Water heater electric voltage protection circuit and water heater | |
| CN208060668U (en) | A kind of fault detecting tool and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Applicant after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 424, building 1, 1500 Wenyi West Road, Cangqian street, Yuhang District, Hangzhou City, Zhejiang Province Applicant before: JOULWATT TECHNOLOGY Inc.,Ltd. |
|
| CB02 | Change of applicant information |